So, how does modern medicine explain this ancestral wisdom of blood deficiency causing sinew contracture? Calf cramps that visit at night, namely nocturnal leg cramps, often stem from a combination of multiple causes. One of the most common causes is electrolyte imbalance and dehydration. When you sweat heavily or fail to drink enough water, the concentration of electrolytes in your body, such as sodium, potassium, calcium, and magnesium, easily becomes disrupted. These electrolytes play a key role in muscle contraction, muscle relaxation, and neurotransmission. If their levels change suddenly, muscle cells become excessively excitable, making them prone to convulsion. At night, muscles can become even more vulnerable because the fluids and electrolytes consumed during daytime activities have not been replenished.
Second is muscle fatigue and overuse. When you stand or walk a lot during the day, or after strenuous exercise, fatigue substances accumulate in the muscles or micro-damage occurs, increasing the muscles' tendency to contract on their own even while resting at night. In particular, because calf muscles are far from the heart and have relatively less smooth blood circulation, fatigue can accumulate more readily.
Third are nervous system issues. During sleep, the regulation of signals sent from the brain to the muscles shifts subtly, and if an abnormality occurs in nerve signal transmission during this process, a convulsion can develop. When nerves leading to the legs are compressed or damaged due to spinal conditions such as herniated discs, nighttime cramps can also occur easily.
Finally, the influence of certain conditions or medications cannot be overlooked. Diabetes, thyroid gland dysfunction, kidney disease, and peripheral neuropathy can cause nocturnal leg cramps. Certain medications, such as hypertension medications like diuretics and hyperlipidemia medications of the statin class, can also have side effects that induce muscle spasms. The concept of blood deficiency described in Donguibogam can be interpreted in modern medicine as the combined result of diverse factors, including blood circulation issues, nutritional deficiencies, and nervous system hypofunction. Therefore, rather than dismissing them merely as simple fatigue, if cramps occur too frequently or severely, it is essential to seek an accurate cause at a medical clinic. Our body is constantly sending us signals.
